The present invention relates generally to apparatus for automatically handling green ceramic cards or other types of fragile materials in the form of sheets or cards, which apparatus includes a carrier device for receiving and transporting the cards in a flat, planar manner, and in a manner that does not tear or otherwise harm the cards.
Pin grid array interconnect devices for the computer industry are made from what is generally known as green ceramic cards. The term "green" refers to unfired ceramic bodies. The cards are cut from a flexible, fragile green ceramic tape. The tape is cast from a slip or slurry of material contained in a hopper. The slip material is a mixture of ceramic powders, organic binders and solvents. In forming the tape, a wet film of the slip mixture is cast on a supporting strip by a method known as "doctor blading". The wet film dries on the supporting strip to form the green tape before it is subject to further handling.
Generally it has been a practice in the industry to manually handle and transfer the green cards after they are cut or blanked from the fragile tape. This has required a substantial number of people, as the tape was manually slit and cut with knives to form each card, and manually supplied to shuttles or other conveying devices for feeding a blanking press to make the cards. After the cutting or blanking process the cards were manually stacked for further processing in the overall manufacture of the packaging modules. On the occasions of using a frame to support and transfer cards, each card was manually secured to the frame with tape to maintain the card in a flat condition on the frame.
It is necessary that the green cards be smooth and flat. In making the interconnect devices, a plurality of the cards are first stacked together and then co-fired in a multi-layer process. The firing changes the layered cards into a monolithic structure and substrate. To insure the integrity of the process and resulting substrate, the green cards need to be flat so that they lie in intimate contact with each other.
Because the production process has been essentially manual, production losses and costs were high. This was due to the fact that the material of the green ceramic tape and cards is fragile, as it is easily contaminated, broken and torn. In addition, the tape is abrasive, requiring personnel to wear gloves to protect their hands. Gloves are also needed to maintain the tapes and blanks free of fingerprints.